The present invention relates to slow release insecticidal and fungicidal chemical agents incorporated in thermoplastic materials. More particularly, the invention is directed to complexes of non-ionic polymers of 2-ethyl oxazoline (PEOx) with biocides such as ortho-phenylphenol and chlorpyrifos and dispersed in thermoplastic polymeric films and pellets to achieve a reduction in the rate of release of the biocide from the plastic carrier.
It is known in the prior art to incorporate biocidal agents such as chlorpyrifos insecticide into plastic film convertible to bags to protect bananas during their growth period. It is known, as well to impregnate plastic film with ortho-phenylphenol for fungicidal protection.
In such applications, the need for and the desirability of reducing the rate of release of fungicides such as ortho-phenylphenol (O-PP) from film or from plastic pellets so as to achieve long term efficacy is known. A variety of different agents including chelants, complexing agents and other chemicals have been proposed as means to achieve this goal. The concept of utilizing specialized biocidal and fungicidal agents in plastic compositions has found broad acceptance. Extensive research has been conducted to discover and develop products in which the biocidal and fungicidal agents are released from plastic films and from plastic pellets under controlled conditions and over extended time periods. The present invention constitutes an important contribution to this field of research and investigation.